The present invention generally relates to a coil winding apparatus for stators, for example, of electrical machines and the like. More particularly, the present invention relates to improvements in a coil winding apparatus using the method of dropping a coil onto a coil inserting jig while winding a coil around a coil winding frame or spool.
For a coil winding apparatus of the above described type, there has conventionally been proposed an arrangement as shown in FIGS. 1 and 2 which generally includes a coil inserting jig 7 provided with a blade member 8 having a plurality of blades and an insulation guide 9, a coil winding frame or spool 3, a flyer 2, an inclined plate 4, and coil depressing or push rods 5, with a stop 10 being further provided for preventing the coil mounted on the coil inserting jig 7 from being undesirably raised or floated. In the above known arrangement, the flyer 2 with the electric wire 1 extended therethrough is rotated around the spool 3 to wind the electric wire 1 around said spool 3, and thus the coil 6 is formed. On the other hand, the inclined plate 4 is subjected to a rocking motion in synchronous relation with the rotation of the flyer 2 so as to vertically move the coil push rods 5. The coils 6 formed around the spool 3 one after another are sequentially downwardly drawn out by the vertical motions of the coil push rods 5, and are dropped onto the coil inserting jig 7. Upon completion of the formation of the coil 6 for a first pole, the spool 3 and the coil push rods 5 descend in the direction of the arrow A to place the coil 6 onto the coil inserting jig 7. Subsequently, the intermediate portion 1a of the electric wire 1 is grasped by a pawl (not shown), and the spool 3 and the coil push rods 5 rise to predetermined positions, and then the coil inserting jig 7 is indexed in the direction of the arrow B. At this time, the intermediate portion 1a' of the electric wire 1 grasped by the pawl moves as far as the winding position at 1a", and after the spool 3 descends as far as said winding position, the coil for the next pole is formed in a similar manner as for the first pole, and the electric wire 1 grasped by the pawl is formed into an inter-pole connecting wire for connection between the poles. In the coil winding apparatus using the system of dropping the coil 6 onto the coil inserting jig 7, while winding the coil 6 around the spool 3 as described above, it is absolutely necessary that the coil 6 accommodated in the coil inserting jig 7 not be raised or floated during the winding operation.
However, in the conventional coil winding apparatuses, since a fixed type stop 10 is employed, a space x which allows the coil push rods 5 to pass therethrough is required between the stop 10 and the insulation guide 9 provided in the coil inserting jig 7. Therefore, the coil 6 accommodated in the coil inserting jig 7 is likely to be floated or raised either by the functioning of the pawl which grasps the inter-pole connecting wire through the space x so as to lift the coil up to the winding position or by spring-back of the coil 6 wound in the above described manner, thus making the winding operation difficult to perform. Furthermore, when the coil 6 has run over the stop 10 during the indexing of the coil inserting jig 7, the coil 6 thus raised is floated, also resulting in difficulties in the winding.
In another known coil winding apparatus proposed, for example, in U.S. Pat. No. 3,872,897, similar inconveniences as described in the foregoing are also encountered.